title: XYLH encodes a xylose/H+ symporter from the highly related yeast species Debaryomyces fabryi and Debaryomyces hansenii.
abstract: The closely related yeasts Debaryomyces fabryi and Debaryomyces hansenii are excellent xylose consumers. We previously described the activity of a high-affinity xylose/H(+) symport from an industrial strain of D. hansenii subsequently reclassified as D. fabryi. We now report the identification of the gene encoding this permease, AY347871.2. This was retrieved from D. fabryi gDNA using a degenerate primer PCR strategy, based on conserved regions from the amino acid sequences of three well-characterized bacterial xylose/H(+) symporters. This sequence is 86% identical to another, DEHA2C11374p from D. hansenii type strain. DEHA2C11374p was conceptually ascribed to the major facilitator superfamily. The putative amino acid sequence of AY347871.2 and DEHA2C11374p presented a hydrophobicity pattern compatible with plasma membrane proteins. The last was functionally expressed in Saccharomyces cerevisiae. The sensitivity of transport activity to a protonophore confirmed its dependence on proton motive force, as expected from a symporter. We named D. fabryi AY347871.2 and D. hansenii DEHA2C11374p as XYLH from Xylose/H(+) symport. Based on the very high similarity, we suggested that Scheffersomyces stipitis Xut3 and Aspergillus nidulans AN8400.2 may also encode xylose high-affinity permeases.
authors.affiliation: Centre of Molecular and Environmental Biology (CBMA), Department of Biology, University of Minho, Braga, Portugal.
authors.forename: Danielly
authors.initials: D
authors.lastname: Ferreira
authors.forename: Alexandra
authors.initials: A
authors.lastname: Nobre
authors.forename: Marta Luisa
authors.initials: ML
authors.lastname: Silva
authors.forename: Fábio
authors.initials: F
authors.lastname: Faria-Oliveira
authors.forename: Joana
authors.initials: J
authors.lastname: Tulha
authors.forename: Célia
authors.initials: C
authors.lastname: Ferreira
authors.forename: Cândida
authors.initials: C
authors.lastname: Lucas
mesh_terms: D001233:Aspergillus nidulans / Q000201:enzymology / Q000235:genetics; D055165:Debaryomyces / Q000145:classification / Q000201:enzymology* / Q000235:genetics*; D005656:Fungal Proteins / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011522:Protons; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D027981:Symporters / Q000235:genetics* / Q000378:metabolism*; D014994:Xylose / Q000378:metabolism*
chemical_list: D005656:Fungal Proteins; D011522:Protons; D027981:Symporters; D014994:Xylose
keywords: Debaryomyces; high-affinity permease; proton symporter; xylose